Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * kernel userspace event delivery |
| 3 | * |
| 4 | * Copyright (C) 2004 Red Hat, Inc. All rights reserved. |
| 5 | * Copyright (C) 2004 Novell, Inc. All rights reserved. |
| 6 | * Copyright (C) 2004 IBM, Inc. All rights reserved. |
| 7 | * |
| 8 | * Licensed under the GNU GPL v2. |
| 9 | * |
| 10 | * Authors: |
| 11 | * Robert Love <rml@novell.com> |
| 12 | * Kay Sievers <kay.sievers@vrfy.org> |
| 13 | * Arjan van de Ven <arjanv@redhat.com> |
| 14 | * Greg Kroah-Hartman <greg@kroah.com> |
| 15 | */ |
| 16 | |
| 17 | #include <linux/spinlock.h> |
| 18 | #include <linux/socket.h> |
| 19 | #include <linux/skbuff.h> |
| 20 | #include <linux/netlink.h> |
| 21 | #include <linux/string.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <linux/kobject.h> |
| 23 | #include <net/sock.h> |
| 24 | |
| 25 | #define BUFFER_SIZE 1024 /* buffer for the hotplug env */ |
| 26 | #define NUM_ENVP 32 /* number of env pointers */ |
| 27 | |
Kay Sievers | 0296b22 | 2005-11-11 05:33:52 +0100 | [diff] [blame] | 28 | #if defined(CONFIG_HOTPLUG) |
| 29 | char hotplug_path[HOTPLUG_PATH_LEN] = "/sbin/hotplug"; |
| 30 | u64 hotplug_seqnum; |
| 31 | static DEFINE_SPINLOCK(sequence_lock); |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 32 | static struct sock *uevent_sock; |
Kay Sievers | 0296b22 | 2005-11-11 05:33:52 +0100 | [diff] [blame] | 33 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 34 | static char *action_to_string(enum kobject_action action) |
| 35 | { |
| 36 | switch (action) { |
| 37 | case KOBJ_ADD: |
| 38 | return "add"; |
| 39 | case KOBJ_REMOVE: |
| 40 | return "remove"; |
| 41 | case KOBJ_CHANGE: |
| 42 | return "change"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 43 | case KOBJ_OFFLINE: |
| 44 | return "offline"; |
| 45 | case KOBJ_ONLINE: |
| 46 | return "online"; |
| 47 | default: |
| 48 | return NULL; |
| 49 | } |
| 50 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | /** |
| 53 | * kobject_hotplug - notify userspace by executing /sbin/hotplug |
| 54 | * |
| 55 | * @action: action that is happening (usually "ADD" or "REMOVE") |
| 56 | * @kobj: struct kobject that the action is happening to |
| 57 | */ |
| 58 | void kobject_hotplug(struct kobject *kobj, enum kobject_action action) |
| 59 | { |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 60 | char **envp; |
| 61 | char *buffer; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 62 | char *scratch; |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 63 | const char *action_string; |
| 64 | const char *devpath = NULL; |
| 65 | const char *subsystem; |
| 66 | struct kobject *top_kobj; |
| 67 | struct kset *kset; |
| 68 | struct kset_hotplug_ops *hotplug_ops; |
| 69 | u64 seq; |
| 70 | char *seq_buff; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 71 | int i = 0; |
| 72 | int retval; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 73 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 74 | pr_debug("%s\n", __FUNCTION__); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 75 | |
| 76 | action_string = action_to_string(action); |
| 77 | if (!action_string) |
| 78 | return; |
| 79 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 80 | /* search the kset we belong to */ |
| 81 | top_kobj = kobj; |
| 82 | if (!top_kobj->kset && top_kobj->parent) { |
| 83 | do { |
| 84 | top_kobj = top_kobj->parent; |
| 85 | } while (!top_kobj->kset && top_kobj->parent); |
| 86 | } |
| 87 | if (!top_kobj->kset) |
| 88 | return; |
| 89 | |
| 90 | kset = top_kobj->kset; |
| 91 | hotplug_ops = kset->hotplug_ops; |
| 92 | |
| 93 | /* skip the event, if the filter returns zero. */ |
| 94 | if (hotplug_ops && hotplug_ops->filter) |
| 95 | if (!hotplug_ops->filter(kset, kobj)) |
| 96 | return; |
| 97 | |
| 98 | /* environment index */ |
| 99 | envp = kzalloc(NUM_ENVP * sizeof (char *), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 100 | if (!envp) |
| 101 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 102 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 103 | /* environment values */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 104 | buffer = kmalloc(BUFFER_SIZE, GFP_KERNEL); |
| 105 | if (!buffer) |
| 106 | goto exit; |
| 107 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 108 | /* complete object path */ |
| 109 | devpath = kobject_get_path(kobj, GFP_KERNEL); |
| 110 | if (!devpath) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 111 | goto exit; |
| 112 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 113 | /* originating subsystem */ |
| 114 | if (hotplug_ops && hotplug_ops->name) |
| 115 | subsystem = hotplug_ops->name(kset, kobj); |
| 116 | else |
| 117 | subsystem = kobject_name(&kset->kobj); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 118 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 119 | /* event environemnt for helper process only */ |
| 120 | envp[i++] = "HOME=/"; |
| 121 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 123 | /* default keys */ |
| 124 | scratch = buffer; |
| 125 | envp [i++] = scratch; |
| 126 | scratch += sprintf(scratch, "ACTION=%s", action_string) + 1; |
| 127 | envp [i++] = scratch; |
| 128 | scratch += sprintf (scratch, "DEVPATH=%s", devpath) + 1; |
| 129 | envp [i++] = scratch; |
| 130 | scratch += sprintf(scratch, "SUBSYSTEM=%s", subsystem) + 1; |
| 131 | |
| 132 | /* just reserve the space, overwrite it after kset call has returned */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | envp[i++] = seq_buff = scratch; |
| 134 | scratch += strlen("SEQNUM=18446744073709551616") + 1; |
| 135 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 136 | /* let the kset specific function add its stuff */ |
| 137 | if (hotplug_ops && hotplug_ops->hotplug) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 138 | retval = hotplug_ops->hotplug (kset, kobj, |
| 139 | &envp[i], NUM_ENVP - i, scratch, |
| 140 | BUFFER_SIZE - (scratch - buffer)); |
| 141 | if (retval) { |
| 142 | pr_debug ("%s - hotplug() returned %d\n", |
| 143 | __FUNCTION__, retval); |
| 144 | goto exit; |
| 145 | } |
| 146 | } |
| 147 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 148 | /* we will send an event, request a new sequence number */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 149 | spin_lock(&sequence_lock); |
| 150 | seq = ++hotplug_seqnum; |
| 151 | spin_unlock(&sequence_lock); |
| 152 | sprintf(seq_buff, "SEQNUM=%llu", (unsigned long long)seq); |
| 153 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 154 | /* send netlink message */ |
| 155 | if (uevent_sock) { |
| 156 | struct sk_buff *skb; |
| 157 | size_t len; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 158 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 159 | /* allocate message with the maximum possible size */ |
| 160 | len = strlen(action_string) + strlen(devpath) + 2; |
| 161 | skb = alloc_skb(len + BUFFER_SIZE, GFP_KERNEL); |
| 162 | if (skb) { |
| 163 | /* add header */ |
| 164 | scratch = skb_put(skb, len); |
| 165 | sprintf(scratch, "%s@%s", action_string, devpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 166 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 167 | /* copy keys to our continuous event payload buffer */ |
| 168 | for (i = 2; envp[i]; i++) { |
| 169 | len = strlen(envp[i]) + 1; |
| 170 | scratch = skb_put(skb, len); |
| 171 | strcpy(scratch, envp[i]); |
| 172 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 174 | NETLINK_CB(skb).dst_group = 1; |
| 175 | netlink_broadcast(uevent_sock, skb, 0, 1, GFP_KERNEL); |
| 176 | } |
| 177 | } |
| 178 | |
| 179 | /* call uevent_helper, usually only enabled during early boot */ |
| 180 | if (hotplug_path[0]) { |
| 181 | char *argv [3]; |
| 182 | |
| 183 | argv [0] = hotplug_path; |
| 184 | argv [1] = (char *)subsystem; |
| 185 | argv [2] = NULL; |
| 186 | call_usermodehelper (argv[0], argv, envp, 0); |
| 187 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
| 189 | exit: |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 190 | kfree(devpath); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | kfree(buffer); |
| 192 | kfree(envp); |
| 193 | return; |
| 194 | } |
| 195 | EXPORT_SYMBOL(kobject_hotplug); |
| 196 | |
| 197 | /** |
| 198 | * add_hotplug_env_var - helper for creating hotplug environment variables |
| 199 | * @envp: Pointer to table of environment variables, as passed into |
| 200 | * hotplug() method. |
| 201 | * @num_envp: Number of environment variable slots available, as |
| 202 | * passed into hotplug() method. |
| 203 | * @cur_index: Pointer to current index into @envp. It should be |
| 204 | * initialized to 0 before the first call to add_hotplug_env_var(), |
| 205 | * and will be incremented on success. |
| 206 | * @buffer: Pointer to buffer for environment variables, as passed |
| 207 | * into hotplug() method. |
| 208 | * @buffer_size: Length of @buffer, as passed into hotplug() method. |
| 209 | * @cur_len: Pointer to current length of space used in @buffer. |
| 210 | * Should be initialized to 0 before the first call to |
| 211 | * add_hotplug_env_var(), and will be incremented on success. |
| 212 | * @format: Format for creating environment variable (of the form |
| 213 | * "XXX=%x") for snprintf(). |
| 214 | * |
| 215 | * Returns 0 if environment variable was added successfully or -ENOMEM |
| 216 | * if no space was available. |
| 217 | */ |
| 218 | int add_hotplug_env_var(char **envp, int num_envp, int *cur_index, |
| 219 | char *buffer, int buffer_size, int *cur_len, |
| 220 | const char *format, ...) |
| 221 | { |
| 222 | va_list args; |
| 223 | |
| 224 | /* |
| 225 | * We check against num_envp - 1 to make sure there is at |
| 226 | * least one slot left after we return, since the hotplug |
| 227 | * method needs to set the last slot to NULL. |
| 228 | */ |
| 229 | if (*cur_index >= num_envp - 1) |
| 230 | return -ENOMEM; |
| 231 | |
| 232 | envp[*cur_index] = buffer + *cur_len; |
| 233 | |
| 234 | va_start(args, format); |
| 235 | *cur_len += vsnprintf(envp[*cur_index], |
| 236 | max(buffer_size - *cur_len, 0), |
| 237 | format, args) + 1; |
| 238 | va_end(args); |
| 239 | |
| 240 | if (*cur_len > buffer_size) |
| 241 | return -ENOMEM; |
| 242 | |
| 243 | (*cur_index)++; |
| 244 | return 0; |
| 245 | } |
| 246 | EXPORT_SYMBOL(add_hotplug_env_var); |
| 247 | |
Kay Sievers | 5f123fb | 2005-11-11 14:43:07 +0100 | [diff] [blame^] | 248 | static int __init kobject_uevent_init(void) |
| 249 | { |
| 250 | uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL, |
| 251 | THIS_MODULE); |
| 252 | |
| 253 | if (!uevent_sock) { |
| 254 | printk(KERN_ERR |
| 255 | "kobject_uevent: unable to create netlink socket!\n"); |
| 256 | return -ENODEV; |
| 257 | } |
| 258 | |
| 259 | return 0; |
| 260 | } |
| 261 | |
| 262 | postcore_initcall(kobject_uevent_init); |
| 263 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 264 | #endif /* CONFIG_HOTPLUG */ |